[Discuss-gnuradio] All packets may lose when running benchmark example in gr-digital/examples/narrowband

[Damon]

Hi all,

When I was running benchmark example in gr-digital/examples/narrowband,
all packets may lose. The environment is shown below.
Hardware: USRP N210 with WBX
Software: GNU Radio v3.7.2.1-62-g6195ff3c and UHD_003.006.000-0-g58f4af97

The two USRPs are placed close to each other. The example is run by:
On the TX side: python benchmark_tx.py -f 1.55G -m qpsk -r 200k -M 10
On the RX side: python benchmark_rx.py -f 1.55G -m qpsk -r 200k

Sometimes, all packets could be received. Then I restarted test, nothing
was printed in the terminator on the RX side.
It looks like a random event. I guess there is something wrong with
timing synchronizer in the receive path.
By the way, everything is ok when we do the test with gmsk.

Best regards,
Damon